Retouchable photographic films for duplicating

ABSTRACT

A retouchable photographic film for duplicating comprising a polyethylene terephthalate film, a mat layer strongly adhered to one or both surfaces of the polyester film, an undercoat formed by applying a gelatin-containing dispersion liquor onto the surface of a mat layer, and an emulsion layer containing a photosensitive silver salt or salts formed on the undercoat, said film being characterized by the use, in the formation thereof, of a swelling agent for the polyester film.

United States Patent Inventors Priority l-laruo Takenaka;

Teppei Ikeda; Toshiaki Okiyama; Sueo Miyazaki, all of Kanagawa, Japan 21,500 7 Mar. 20, 1970 Oct. 26, 1971 Fuji Photo Film Co., Ltd. Ashigara-Kamigun, Kanagawa, Japan July 13, 1965 Japan Continuation-impart of application Ser. No.

564,840, July 13, 1966, now abandoned.

RETOUCHABLE PHOTOGRAPHIC FILMS FOR DUPLICATING 9 Claims, 3 Drawing Figs.

US. Cl 96/87 R, 117/1388 F, 117/73 Int. Cl G03c-1/80 Field of Search 96/87, 75

[56] References Cited UNITED STATES PATENTS 2,893,896 7/1959 Beeber etal..... 117/118 2,963,366 12/1960 Kosar et al 96/83 2,999,016 9/1961 Beeber et a1 96/75 3,178,287 4/1965 Sweet et al 96/84 3,353,958 11/1967 Moede 96/87 2,698,239 12/1954 Alles et a1. 96/87 F ORElGN PATENTS 925,069 8/1959 Great Britain 96/87 Primary Examiner- Ronald H. Smith Attorney-Sughrue, Rothwell, Mion, Zinn & Macpeak ABSTRACT: A retouchable photographic film for duplicating comprising a polyethylene terephthalate film, a mat layer strongly adhered to one orboth surfaces of the polyester film, an undercoat formed by applying a gelatin-containing disper sion liquor onto the surface of a mat layer, and an emulsion layer containing a photosensitive silver salt'or salts formed on the undercoat, said film being characterized by the use, in the formation thereof, of a swelling agent for the polyester film.

PATENTEDUCI 26 Ian 3,615,554

4 1 3& 4 44 4 444 44444 4 44 2 o o o o c a FIG. 1

FIG: 2

INVENTORS HARUO TAKENAKA TEPPEI IKEDA TOSHIAKI OKIYAMA SUEO MIYAZAKI ATTORNEYS BACKGROUND OF THE INVENTION 1 Field of the Invention The present invention relates to a retouchable photographic film for duplicating comprising a polyethylene terephthalate film which is biaxially oriented and crystallized, hereinafter simply referred to as a polyester film, a mat layer (s) strongly adhered to one or both surfaces of the polyester film, and an emulsion layer containing photosensitive silver salts and being applied to the surface area of one aforementioned mat, whereby an image printed on the photographic film can easily be erased.

2. Description of the prior Art Recording paper consisting of a plastic film and a mat layer adhered thereto has been suggested. In U.S. PAT. NO. 3,100, 722, for example, recording paper comprising a polyester film and a mat layer, which can be marked by means of various kinds of writing, has been disclosed. Such a recording paper comprising a plastic film and a mat layer, however is nothing but a conventional recording paper on which a picture is merely marked by a pencil, an inked pen or with India ink, and is much the same as a conventional one in point of function. A photographic film for duplicating comprising a cellulose acetate film, a polyester film and an emulsion layer containing a photosensitive silver salt or salts, the emulsion layer consisting of a mat surface, has also been proposed. Although a picture printed on such a photographic film for duplicating can be rubbed out with an eraser, the corresponding portion of the film rubbed cannot be retouched for correction.

The retouchable photographic film for duplicating prepared in accordance with the present invention is distinguished from conventional recording film and characterized by the advantages that the image formed on the photosensitive layer can be rubbed out and the corresponding portion of the photographic layer rubbed can be retouched for correction, as well as the faculty by which duplication of an image can be achieved.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a photographic film comprising a polyester film having thereon a mat layer and an emulsion coating containing a photosensitive silver salt or salts, such that an image formed thereon can be easily erased and the erased portion of the film can be further retouched for correction.

Another object of the present invention is to increase the adhesion of a mat layer to a polyester film by incorporating polyester resin into a binder for the mat layer.

Still a further object of the present invention is to improve the preservability of a photosensitive material by employing an emulsion of a photosensitive silver salt or salts and to make the photosensitive material free from discoloring.

Another object of the present invention is to increase the adhesion between the emulsion coating layer containing a photosensitive silver salt or salts and the mat layer, by providing an intermediate layer composed of gelatin.

A further object of the present invention is to increase adhesion between the mat layer and the intermediate layer composed of gelatin by incorporating cellulose nitrate into a binder contained in the mat layer.

These objects of the present invention may be achieved by the use of a swelling agent for the polyester film. The swelling agents are selected from among a particular group of such agents, as more fully defined hereinafter, and result in increased hardness as well as increased adhesion between the layers.

BRIEF DESCRIPTION OF THE DRAWING Other objects of the present invention will become apparent from the ensuing specification and attached drawing in which;

FIG. 1 is a cross-sectional view showing a first embodiment of the photographic element of this invention;

FIG. 2 is a cross-sectional view showing another embodiment of the photographic element of the present invention; and

FIG. 3 is a cross-sectional view showing still another embodiment of the photographic element of the present invention.

DETAILED DESCRIPTION OF THE INVENTION Polyethylene terephthalate is employed as a supportinghase member to take advantage of its optical, chemical and physical properties which make it suitable as a base material of a photographic film. As a binder for the mat layer, a copolymerized ester, selected from the group consisting of terephthalic acid and isophthalic acid and glycols, is used together with cellulose nitrate mixed therewith. The use of cellulose nitrate improves the adhesion between an intermediate layer composed of gelatin and the mat layer. By incorporating one or more agents for swelling the polyester film into organic solvents for the copolyester, and cellulose nitrate, the adhesion between the mat layer and the polyester film is so increased that they do not separate from the other, even when the duplicating film is touched with a hard pencil at the time of correction. The thickness of the emulsion layer applied is preferably l-lO microns. If it is too thin, poor image contrast results. If it is too thick, the image is difficult to erase. When a diam-containing photosensitive liquid is used as a photosensitive mat material, good preservability cannot result and there is a tendency to discoloration, so that a photosensitive silver salt or salts are employed. If a mat layer is directly coated with an emulsion layer containing a photosensitive silver salt or salts, the adhesion therebetween is very poor, thus necessitating an intermediate layer (undercoat) for preventing contact between the mat layer and the emulsion layer containing a photosensitive silver salt or salts.

FIG. 1 shows a normal state of a photographic film comprising a support 1, a mat layer 2, an undercoat 3, and a light-sensitive silver halide emulsion layer 4. FIG. 2 shows a photographic film of the same construction as in Flg. I with the exception that a mat layer 2 is formed on one side of the support opposite to the side having coating layers 2, 3 and 4. FIG. 3

shows a photographic film as in FIG. 2 with the exception that an undercoat 5 of polyester, an undercoat 3 of gelatin and a matted layer 6 of gelatin are applied thereto in place of the mat layer 2, in the order described, to form seven layers including the support 1,

The mat layer of the photographic film for duplication may be prepared in accordancewith the method described below. A condensation polyester of at least one dicarboxylic acid selected from the group consisting of terephthalic acid and isophthalic acid and glycols (designated as condensation polyester hereinafter) is dissolved in an organic solvent such as methylene. chloride, ethylene chloride, and trichloroethylene, and the solution is sufficiently blended in a ball mill together with starch, silica and the like added thereto as a matting agent. The use of starch is favorable since it exhibits a white appearance, is free from muddying, and is apt to become fine particles owing to its high degree of dispersion.

Cellulose nitrate of lower viscosity is dissolved in acetone, and to the solution is added an agent for swelling a polyester film and having the composition mentioned hereinafter in order to increase the adhesion against the polyester film, after which is further added ethylene chloride and the like to control viscosity. The resulting solution of suitable viscosity for application is mixed with the original liquid mass, above-mentioned, containing copolyester.

As a solvent for cellulose nitrate, acetone is most favorable from the point of the stability of the resulting solution. The stability of the solution deteriorates when a solvent having a higher or a lower boiling point than that of acetone is used.

The adhesion between a polyester film and the mat layer becomes poor if an agent for swelling the polyester film is not incorporated. The amount of the swelling agent is preferably 3-8 percent, based on the weight of the total solvents. As an agent for swelling the polyester film, the following are examples: phenol and derivatives thereof such as resorcin, orthochlorophenol, parachlorophenol and cresol; benzoic acid, salicylic acid, esters of salicylic acid, monochloroacetate, trichloroacetate, tn'fluoroacetate, 2- nitropropanol, benzyl alcohol, benzaldehyde, acetonitrile, acetophenone, benzamide, benzonitrile, methyl nicotinate and the like.

The thickness of the mat layer after drying is preferably 3-10 microns, most favorably 5-8 microns. When the copolyester alone is used as a binder for the mat layer, the adhesion between the mat layer and an undercoat of getatin is poor, and the mat layer is apt to detach from the undercoat of gelatin at the time when an emulsion layer, containing a photosensitive silver salt or salts, is attached to the undercoat.

By incorporating cellulose nitrate into the copolyester, the adhesion between the mat layer and the undercoat of gelatin is improved, and no detachment is observed. The amount of cellulose nitrate is preferably 5-20 percent based on the weight of the copolyester, and most favorably 8-16 percent. As the cellulose nitrate, one having the viscosity of %%z seconds is preferred. Themat layer is coated with an undercoat of gelatin for improving the adhesiveness between the mat layer and an emulsion layer containing a photosensitive silver salt or salts.

The following are examples for preparing a photographic film for duplicating in accordance with the present invention EXAMPLE l 100 parts by weight of Videne (commercially available copolymer of the system: isophthalic acid-terephthalic acidethylene glycol, manufactured by Good Year Tire & Rubber Company) is dissolved in 900 parts of ethylene chloride, and the solution is blended together with 20 parts of starch and eight parts of silica in a ball mill for 120 hours, to prepare an original liquid mass.

12 parts of cellulose nitrate of the viscosity of k seconds is dissolved in 100 parts of acetone, and further added with 200 parts of phenol-tetrachloroethane (lzl) and 500 parts of ethylene chloride. The resulting solution is mixed with the original aforementioned liquid mass. After sufficient agitation, the solution is applied onto the surface of a polyester film, followed by drying. The coating is 6 microns in thickness after drying.

In order to improve the adhesion between the mat layer thus produced and an emulsion layer containing a photosensitive silver salt or salts, the mat layer is coated with a liquid composition comprising one part of gelatin, 27 parts of water, 0.3 parts of acetic acid, 24 parts of methanol and 70 parts of ethylene chloride, to thereby form an undercoat of gelatin thereon. A solution composed of a mixture of 0.4 parts of the copolyester, in the system of isophthalic acid, ethylene glycol and triethylene glycol, and 0.6 parts of cellulose nitrate of A second viscosity, and a mixture of 70 parts of ethylene chloride and 30 parts of acetone, is applied onto the other side of the polyester film, and the above-mentioned liquid composition is further applied thereon.

Thereafter, an emulsion containing a photosensitive silver salt or salts (previously matted) is applied onto the mat layer on the polyester film, and a gelatin composition previously matted is applied onto the opposite side, on which no mat layer is attached, of the polyester film. The thicknesses of the former and the latter are 3 microns, respectively. An image printed on the photographic film for duplicating thus prepared can be easily rubbed off by means of a sand rubber wetted with water, and the photographic film thus rubbed still remains retouchable for correction.

EXAMPLE 2 100 parts of Videne dissolved in 900 parts of ethylene chloride is blended together with 15 parts of starch and l0 parts of silica as a matting agent, in a ball mill for 96 hours, to prepare an original liquid mass.

10 parts of cellulose nitrate of /6 second viscosity dissolved in 90 parts of acetone is added with 200 parts of resorcintetrachloroethane (1:1) and 400 parts of ethylene chloride and the resulting solution is mixed with the original liquid mass above-mentioned. After sufficient agitation, the mixture is applied onto the both surfaces of the polyester film, the thickness of both coating films being 8 microns after drying, respectively.

The gelatin composition as in the preceding example is applied, to form an undercoat onto the surface of the mat layer on one side of the polyester film for the purpose of increasing the adhesion of an emulsion layer containing a photosensitive silver salt or salts. An emulsion containing a photosensitive silver salt or salts is then applied onto the surface of the undercoat. The thickness of the emulsion layer after drying is 3 microns. An image printed on the photographic film for duplicating thus prepared can be easily rubbed out by means of a sand rubber-wearing water, and the photographic film thus rubbed still remains retouchable.

EXAMPLE 3 Following the same procedure as in example 2, with the exception that monochloracetic acid is used in place of resorcin, approximately the same product as in example 2 is obtained.

EXAMPLE 4 By means of the same processes as in example 2, with an exception that trichloroacetic acid is used in place of resorcin, a

' product exhibiting approximately the same availability when compared with the product in example 2 is obtained.

An unnecessary portion of a transferred image printed on the photographic film of the present invention can easily be rubbed off by means of a sand rubber wetted with water, and, if necessary, the original image printed can be corrected by retouching the mat layer disclosed. In a case where the mat layer is attached to both surfaces of the polyester film, it is natural that both sides of the photographic film are retouched for correction. V

EXAMPLES 5-28 Example No. Composition 5 polyester (terephthalic acid-isophthalic acidethylene-glycol-copolymer)+ nitrocellulose 6 polyester (terephthalic acid-ethyleneglycoltriethylenc-glycol copolymer)+ nitrocellulose 7 polyester (isophthalic acid-cthyleneglycoltricthylene-glycol copolyrner)+ nitrocellulose 8 composition of example 5 matting agent 9 composition of example 6 matting agent composition of example 7 matting agent composition of example 8 phenol as a swelling agent composition of example 9 phenol as a swelling agent composition of example l0 phenol as a swelling agent composition of example 8 resorcinol as a swelling agent composition of example 9 resorcinol as a swelling agent composition ofexample l0'+ resorcinol as a swelling agent composition of example 8 p-cresol as a swelling agent composition of example 9 p-cresol as a swelling agent composition of example 10 p-cresol as a swelling agent composition ofexample 8 cresol as a swelling agent composition of example 9+ cresol as a swelling agent composition of example l cresol as a swelling agent composition of example 8 benzyl alcohol as a swelling agent composition of example 9 benzyl alcohol as a swelling agent composition of example 10 benzyl alcohol as a swelling agent composition of example 8 acetophenone as a swelling agent composition of example 9 acetophenone as a swelling agent composition of example 10 +acetophenone as a swelling agent The above compositions were prepared as follows, all parts being by weight:

Compositions -7 In 900 parts of ethylene-chloride are dissolved 100 parts of polyester and this mixture added to a solution of 12 parts of RSI/2 nitrocellulose (manufactured by Dainippon Cellophane Co., Ltd. dissolved in a mixture of 100 parts of acetone and 500 parts of ethylenechloride and thereafter stirred. The resulting solution is then coated on polyester film to provide a dry coating layer of 2p. in thickness.

Compositions 8-10 Compositions 1 1-28 In 900 parts of ethylene chloride are dissolved 100 parts of polyester. 20 parts of starch and eight parts of silica as a matting agent are then added and the mixture stirred for 120 hours in a ball mill to produce a mother solution. In 100 parts of acetone are dissolved 12 parts of RSI/2 nitrocellulose and this solution added to the mother solution. Further, a mixture of 200 parts of a mixture of swelling agents, as set forth above, and tetrachloroethane (1:1) and 500 parts of ethylene chloride are added to said mother solution and stirred to prepare the compositions of examples 1 1-28, respectively. The solutions thus prepared are then coated so as to provide a dry thickness 0f6 [.L.

The compositions were tested for hardness and adhesion as follows:

ADHESION TESTS Polyester films coated with the above compositions are cut into 15 cm. squares and 11 lines at intervals of 1 cm. in each direction are scribed by razor perpendicularly so as to form grooves through said coated layer thus forming squares in Proportion of Coating Stripped from Film Base Adhesion Value A... none B... less than l/SO C... 1/50 to l/lO D... l/IO to 1/5 E... Over 1/5 Values of A or B represent compositions of practical utility. Compositions having a value of C have utility only in limited applications. Compositions having values of D or E are unsuitable for use.

PENCIL l-IARDNESS TESTSv These tests were used to show the hardness of the film obtained. The films are considered useful if they are not scratched by a pencil having a hardness of 9H or above, and of limited usefulness if scratched by a pencil having a hardness of 7H. In the results shown for the films listedbelow, the following coding system was used to indicate the results obtained.

Scratched By Hardness Value uom RESULTS Coated layer Adhesion Value Hardness Value (Example No.)

5 the polyester B B 6 A B 8 D E 9 D D 10 E E t l A B to B B I) A A 23 B B 24 B B 25 C C THe above date shows that when a matting agent is incorporated into a coated layer consisting of polyester and nitrocellulose, the adhesion between the polyester film and the coated layer, as well as the hardness of coated layer, become poor. (Compare the results of examples 5-7 with those obtained with examples 8-10 Adhesion and hardness are improved by incorporating a swelling agent for the polyester despite the presence of such a matting agent, as shown by examples 1 1-28.

The above data also indicates that the order of effectiveness of the swelling agents is as follows: parachlorophenol pheno l resorcinal=cresol acetophen0ne benzylalcohol.

It may further be seen that the adhesive strength and hardness of the mat layer varies as follows, depending on the identity of the polyester employed: terephthalic acidethyleneglycol-triethyleneglycol terephthalicacid isophthalic acidethyleneglycol isophthalic acid ethyleneglycol-triethyleneglycol.

EXAMPLES 29-46 In order to illustrate the importance of employing the recited swelling agents, the agents of the present invention were compared with another well-known polyester swelling agent, acetone, to show that the results, in terms of adhesion and hardness, are entirely different from those obtained by using the swelling agents of the present invention.

The following compositions were tested:

Example No. Composition 29 composition of example 8 acetone as a swelling agent 30 composition of example 9 acetone as a swelling agent 3| composition ofexample acetone as a swelling agent composition of example 8 prepared using methyl ethyl ketone instead of acetone as the solvent composition of example 9 prepared using methyl ethyl ketone instead of acetone as the solvent composition of example 10 prepared using methyl ethyl ketone instead of acetone as the solvent composition of example 32 phenol as a swelling agent composition of example 33 phenol as a swelling agent composition of example 34 phenol as a swelling agent composition of example 32 resorcinol as a swelling agent composition of example 33 resorcinol as a swelling agent composition of example 34 +resorcinol as a swelling agent composition of example 32 p-chlorophenol as a swelling agent composition of example 33 p-chlorophcnol as a swelling agent composition of example 34 p-chlorophenol as a swelling agent composition of example 32 acetone as a swelling agent composition of example 33 acetone as a swelling agent composition of example 34 acetone as a swelling agent The above compositions were prepared as follows, all parts being by weight:

Compositions 29-31 Into 900parts of ethylene chloride are dissolved 100 parts of polyester. 20 parts of starch and 8 parts of silica as a matting agent arethen added and the mixture kneaded for 120 hours in a ball mill to form a mother solution. A mixture of 12 parts of RS 1/2 nitrocellulose, 100 parts of acetone, 200 parts of acetone as a swelling agent andSOO parts of ethylene chloride is added to the mother solution and stirred. The resulting solution is coated on the polyester to obtain a coating having a dry thickness of 6 [.L.

Compositions 32-34 The procedure for preparing the compositions of examples 8-10 is followed, except that instead of acetone as the solvent for cellulose nitrate, an equivalent amount of methylethyl ketone is used.

Compositions 35 -46 lnto 900 parts of ethylene chloride are dissolved 100 parts of polyester. 20 parts of starch and eight parts of silica as a matting agent are then added and the mixture kneaded for 120hours in a ball mill to form a mother solution. To 100 parts of methylethyl ketone are dissolved RS l/2 cellulose nitrate. 200 parts of the swelling agent (phenol in (3l)-(33), resorcinol in (34-(36). paraohlorophenol in (37-(39), acetone in (40)-(42) tetrachloroethane (lzl) and 500 parts of ethylene chloride are added to the mixture. After stirring it is coated on polyester film in6p. thick after drying.

The above compositions were tested to determine adhesion and hardness values in the same manner as the compositions of examples 5-28. The results are as follows:

hardness of the film are not improved.

As is clear from the above tests on examples 8 -l0 and 32 -34, when methylethyl ketone is used instead of acetone as the solvent for cellulose nitrate the adhesion and hardness are not changed.

As is clear from the tests conducted on examples 35 -44, when methylethyl ketone is used as a solvent for cellulose nitrate, excellent adhesion and hardness are obtained. However, as is clear from the tests conducted on the compositions of examples 44 -46, when acetone is used as a swelling agent, the adhesion and hardness is severely degraded.

Accordingly, it will be seen that the use of acetone as a swelling agent does not improve the adhesion and hardness of the polyethylene terephthalate films of the present invention, whereas the use of the swelling agents of the present invention clearly enhances these properties.

What is claimed is:

1. A photographic film for duplicating, comprising a polyethylene terephthalate film which is biaxially oriented and crystallized, a mat layer attached onto one side of the film formed by applying thereto a dispersion solution comprising a binding agent composed of a polyester derived from the condensation reaction of glycols with at least one member selected from the group consisting of terephthalic acid and iso-phthalic acid and of cellulose nitrate, at least one agent for swelling the polyester film and one or more organic solvents therefore, the swelling agent being a member selected from the group consisting of phenol and derivatives thereof from the group resorcin, orthochlorophenol, para-chlorophenol and cresol; benzoic acid, salicylic acid, esters of salicylic acid, monochloroacetic acid, trichloroacetic acid, trifluoroacetic acid, 2-nitropropanal, benzyl alcohol, benzaldehyde, acetonitrile, acetophenone, benzamide, benzonitrile and methyl nicotinate and at least one matting agent selected from the group consisting of starch and silica, an undercoat formed by applying a gelatin-containing dispersion liquor onto the surface of a mat layer, and an emulsion layer containing a photosensitive silver salt or salts formed on the undercoat.

8. A photographic film as in claim 7 wherein the amount of cellulose nitrate employed ranges from 8.0 to 16 percent based on the weight of the copolyester.

9. A photographic film as in claim 1 wherein the viscosity of the cellulose nitrate employed ranges from one-half to oneeighth seconds. 

2. A photographic film as in claim 1 where mat layers are attached onto both sides of the film.
 3. A photographic film as in claim 1 wherein thE amount of swelling agent is between 3 to 8 percent by weight of the organic solvent.
 4. A photographic film as in claim 1 wherein the thickness of the emulsion layer applied ranges from 1 to 10 microns.
 5. A photographic film as in claim 1 wherein the thickness of said mat layer ranges from 3 to 10 microns.
 6. A photographic film as claimed in claim 5 wherein the thickness of said mat layer ranges from 5 to 8 microns.
 7. A photographic film as in claim 1 wherein the amount of cellulose nitrate employed ranges from 5.0 to 20 percent based on the weight of the copolyester.
 8. A photographic film as in claim 7 wherein the amount of cellulose nitrate employed ranges from 8.0 to 16 percent based on the weight of the copolyester.
 9. A photographic film as in claim 1 wherein the viscosity of the cellulose nitrate employed ranges from one-half to one-eighth seconds. 